Improved shock absorber



t invention, .and Figure Patented Mar. Z2, 1938 Eugne Laugaudin, Paris,VFrance Application July 1v, 1935', serial Nb. 3119,12

France July-18, `1934! f 6 claims. (o1. 1267-65) The presentinventionrelates to improvements in shock absorbers constituted by a cylindercontaining a fluid, preferably a compressed gaseous fluid; air `forexample, lnwhich moves by translation or rotation, a main piston, which,under the actionof the shocks which it receives,I further compresses theair in the cylinder: this compressed air (and f further `compressed,under the action `oi the shocks), acts on a second or loose piston whichtransmits the pressure it receives to a liquid fluid interposed betweenthe cylinder and the piston which, in its turn,yacts on one or morescraper cups :of` flexible `material or elastic metal having a taperededge arranged between the pistonand the cylinder; the pressure `exertedon this `liquid fluid pressing the tapered edge of the cups on thepistonand ensuring perfect fluid-tightness of the joint thus formed. I

Figure. 1 is a vertical section of the shock absorber. s 1 f y Figure 2lsya modification of the invention.

Figure 3 shows "another modification of the ,4 shows a furtherlmodification of the invention. y

\ Aswillbeseen from Figure 1 the apparatus is composed of a cylinder Ilthe lower part IIa of which is oflargerdiameter than the upper part I Ithe piston I4 is terminated by a head I5 forming a guide, lodged in thepart II oi the cylinder;

this head is provided with `holes I6. 1 l f A scraper cup` II` offlexible material or elastic metal with a tapered edge for example, is`en gaged upon the piston I4 and itsbase rests on a p shoulder ofv theYcylinder and with its tapered "35 edge pressing on the periphery of thepiston, a sleeve -I 9, pierced withholes 2,0, Y, at its lower I part,presses upon the base of the cup Il and holds it .in place as `willbeexplained hereinafter. In the annular space formed between the wall ofthe part I la of the cylinder and the said sleeve is housed an annularcup 2 I l constituting a ,loose pistonf"` A f Y `1 fg' A secondcuplhaving a tapered edge 22, of the same typev as theoup I1, is engagedon the ypiston Hnd itsbase presses against theloweiipart of the ,sleeveI9; thus as will be seen, the tapered edges of these two cups are facingone another; a plug 23 screwed on to the lower parti la holds the cupsI'l and 22 in' pla`ceth'e fixed spacing between which is ensured by thesleeve I9. Element I2se`rves 'forthe introduction of the' oil intendedto obtain fluid-tightness. I3 is the valve for` the introduction of theair compressed in cylinder II.l `(londuits 24 place the two parts thecylinder II of the cylinder II `and Ila into communication with eachother.

The working operation will easilybe understood; under the action of theshocks, the piston moves `in the cylinderiurther compressing the 6compressed airwhich it contains; thislatter compressed air, in passing`through the holes i6, acts on the annularl cup, or the loose piston 2land the latter transmits to the oil'the pressure which it receives and,throughtheholes 2B of the sleeve I9, transmits thispressure to thescraper cups il and 22 `the tapered edges of which are thus pressedvaccurately lagainst the piston `It thus ensuring perfectfluid-tightness.

The constructional form shown in Figure 2 is 15 a modification ofthedevice illustrated in Figrn this modification s the piston I4 before,provided with va head A I5 provided with conduits I6; the annular cup 2lforming theloose piston of Figure V1 is combined with the scraper cup I1of Figure 1; thus a free cup 21 is obtained in the form of an annularcup which is engaged on the piston I4 and its stroke is limited in onedirection by the shoulder II'b of the cylinder; the `internal wall ofthis cup which is in contact with the piston has a tapered edgeas inFigure l and its externai wall in Contact with the cylinder serves as aguide; on the piston Ill` is engaged another cup 28 similar to thepreviousone and xed by screwing or the like; on the lower part of thecylinder, the tapered edges of the two cups are arranged face to faceasalready mentioned; I2 is the oriiice for the introduction Vof the oil;I3 is theQvalve forv the introduction of the compressed air intoA Theoperation is similar to thataccording to Figure 1. The compressed aircontained in tbc topof the cylinder and further compressed by theshocks, passes through the holes I6 of the head I5 and this pressurel isexerted directlyon the member 21 forming the loose piston and scrapercup tending` to move -the said member 21 towards themember 28; underthis pressure the oil presses the tapered edges of the,` parts 21-(28accurately against the piston in order to ensure perfect fluidtightness.y i

FigureB showsanother constructional variation of the exampleillustrated' in Figure 1, but in `this modification the cup 2|,insteadof being annular 50 land-,surrounding the whole of the piston, isarranged in a small auxiliary cylinder V29 and constitutes a smallpiston 30 on which the pressure of the :further compressed air isexerted; the ref- 55 erence numerals of Figure 1 are used to indicatethe same parts in this modification.

The operation is the same as in Figure 1, 20a being an opening on theauxiliary cylinder for the passage of the oil.

The apparatus could also operate with a vacuum in the cylinder, in whichcase the piston moves outwardly under the action of shocks. This wouldrequire certain slight modications, which are indicated in Figure 4, itbeing understood that the valve Il is replaced by tubing with a closingmember which may be connected with a vacuum pump in such a manner as tocomplete the vacuum in the cylinder upon placing the members intoposition or where on account of prolonged use a small quantity of airmay accidentally be introduced into the cylinder.

There is no longer any necessity to provide a communication between thecylinder and the auxiliary cylinder. The ducts 24 are omitted and alsothe ducts I 5 in the piston head. As liquid. use will be made of a tluldhaving a high surface tension, forexample mercury.

Finally, atmospheric pressure acts upon the piston 30a of the sma'llauxiliary piston. in order to obtain the necessary pressure to apply thetapered edge of the cups against the piston.

This small piston 30a may also be subjected to the action of a spring3|, tending to press it against the liquid fluid, which acts upon thecups, through the duct 32 and the corresponding apertures in the sleevei9.

It should be pointed out that in all these constructional forms thetapered edges ot the cups form scrapers for the oil which may adhere tothe piston.

Each of the iluids used in the apparatus may be liquid or gaseous;preferably the duid having the highest surface viscosity or tensionbeing placed in the part forming the seal or joint.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent is:-

1. A shock absorber comprising a cylinder, a main piston ln saidcylinder having a non-fluid tight guiding head, a second piston freelydisplaceable within said cylinderand adapted to separate a mass ofliquid iluid and a mass of gaseous fluid contained outside said mainpiston and in said cylinder, and sealing means formed of at least oneilexible cup washer having a tapering skirt interposed between thecylinder and the main piston whereby as the result of pressure exertedon the second piston and transmitted to the liquid uid the said taperingskirt of said sealing means is pressed closely against the main piston.

2. A shock absorber comprising a cylinder, a main piston in saidcylinder having a non-duid tight guiding head, a second piston freelydisplaceable within said cylinder and adapted to separate a mass 0Iliquid uid and a mass of gaseous fluid contained outside said mainpiston and in said cylinder, and sealing means formed of at least oneexible cup washer mounted on said cylinder, said iiexible cup washerinterposed between the cylinder and the main piston and having atapering skirt whereby as the result of pressure exerted on the secondpiston and transmitted to the liquid fluid the said tapering skirt ispressed closely against the main piston.

3. A shock absorber comprising a cylinder, a main piston including aguiding head dividing the cylinder into an upper and a lower chamber andhaving communication between said chambers, an auxiliary chambercontained in said cylinder and having communication with said lowerchamber, said auxiliary chamber containing a second piston adapted toseparate a mass of liquid fluid and a mass of gaseous iiuid contained insaid latter chamber, and opposed exible cup washers between saidcylinder and piston each having a tapering skirt spacedly arranged toform a space therebetween having communication with said mass of liquidduid in said auxiliary chamber whereby as the result of pressure exertedon the second piston and transmitted to said mass of liquid uid thetapering skirts of said opposed iiexible cup washers are pressed closelyagainst the piston.

4. A shock absorber comprising a cylinder, a main piston including aguiding head dividing the cylinder into an upper and a lower chamber andhaving communication -between said chambers. an auxiliary chambercontained in said cylinder and having vcommunication with said lowerchamber, said auxiliary chamber containing a second piston adapted toseparate a mass of liquid uid and a mass of gaseous iiuid contained insaid latter chamber, and opposed ilexible cup washers on said cylinder,each formed by an annular member having a tapering skirt spacedlyarranged to form a space therebetween having communication with saidmass of liquid fluid in said auxiliary chamber whereby as the result ofpressure exerted on said second piston and transmitted to said mass ofliquid duid the tapering skirts of said opposed flexible cup washers arepressed closely against the piston.

5. A shock absorber comprising a cylinder, a main piston including aguiding head having communication between both sides thereof, a secondpiston displaceable within said cylinder and adapted to separate a massof liquid uid and a mass of gaseous iluid contained in Isaid cylinder,said second piston having a tapering exible skirt in contact with saidpiston, and a ilexible cup washer secured on said cylinder below saidmass of liquid fluid and having a tapering skirt in' contact with saidpiston, whereby as the result of pressure exerted on the second pistonand transmitted to the liquid fluid, said tapering skirts are pressedclosely against the piston.

6. A shock absorber comprising a cylinder, a main piston having anon-uid` tight guiding head, an auxiliary chamber contained in saidcylinder and containing a second piston adapted to separate a mass ofliquidv fluid and air contained in said chamber, said second pistonhaving spring means acting against said liquid iiuld in said auxiliarychamber, and opposed ilexible cup washers on said cylinder, each formedby an annular member having a tapering skirt spacedly arranged to form aspace therebetween having communication with said mass of liquid iluidin said auxiliary chamber whereby as the result of pressure exerted onsaid second piston and transmitted to said mass of liquid uid thetapering skirts of said opposed flexible cup washers are pressed closelyagainst the piston.

EUGENE LAUGAUDm.

